Cover for electrolytic cell with mercury cathodes and adjustable anodes

ABSTRACT

A cover for a horizontal electrolytic cell having mercury cathode and adjustable anodes and in which the anodes have vertical current carrying shafts extending through the cover, the cover having downwardly projecting bulges at the passage points of the anode shafts, thereby effecting a saying in the material for the shafts and a gain in voltage because of the short current feed.

3647670 COVER FR ELECTROLYTIC CELL WEH-I MERCURY CATHODES AND ADJUSTABLE ANUDES Luciano Mos and Gerhard Heuser, Dortmund, Germany,

assignors 10 Friedrich Uhde GmbH, Dortmund, Germany Filed May 14, 1969, Ser. N0. 824,656 Claims priority, application Germany, May 17, 1968, l 17 71 392.7 Int. Cl. C22d 1/04, 1/02 U.S. Cl. 204219 2 Claims ABSC'I F THE DISCLOSURE A cover for a horizontal electrolytic cell having mercury cathode and adjustable anodes and in which the anodes have vertical current carrying shafts extending through the cover, the cover having downwardly projecting bulges at the passage points of the anode shafts, thereby elfecting a saving in the material for the shafts and a gain in voltage because of the short current feed.

BACKGROUND OF THE INVENTION Electrolytic cells provided With mercury cathode and adjustable anodes have plate shaped anodes, to which electrical current is supplied through anode shafts or rods which are guided through the cel1 cover. With forrner embodiments of graphite anodes, these anode shafts are likewise made of graphite for the prevention of corrosion by the corrosive gas formed during the electrolysis. In order, however, to maintain the drop in voltage in the anode shafts as 10W as possible upon high current intensities of more than 1,000 amperes per anode, the graphite anode shafts were replaced by copper shafts, which were surrounded by protective coverings or casings to guard against corrosion. The protective coverings or casings consist of porcelain or a synthetic material having high chemical resistance. The lengths of the anode shafts in the known embodiments were determined by the height of the brine level and the height of the gas space or chamber required over the brine.

The cell cover seals the cell against the escape of gas upwardly and may at the same time serve as a supporting device for the anodes. The anode shafts to enable adju5tment of the anodes are axially slidable With respect to the cover. For a common adjustment of the anodes, the cover which carries the anodes, is sealed elastically With respect to the cell rim.

SUMMARY OF THE INVENTION In accordance With the invention, a novel cover is prodnced for a horizontal electrolytic cell having mercury cathode and adjustable anodes, and particularly a cover which carries the anodes and is elastically sealed to the cell rim. An important feature is the provision of downwardly formed bulges at the Passage points of the anode shafts.

Such a cover cross section has the advantage, that because of the proximity of the sealing point between anode shaft and seil cover and the anode plate, the expensive anode copper shafts enclosed within a casing protective against corrosion may be made appreciably shorter, so that in addition to the saving in material, a gain in voltage is attained due to the shorter current feed.

In order that the sealing points of the anodes are readily accessible and to give the cell cover at the same time an increased rigidity in one direction, it is of advantage to make the downward bulges groove-shaped.

nited States Patent O An increased rigidity of the cell cover is required especxally if it does not rest on the cell rim, but is elastically connected to the rim and must also carry the anodes. With respect to flat cell covers, the necessary rigidity may be readily attained in all directions by means cf st1ffening ribs, perpendicularly arranged to the groove shaped bulges. Through the increased rigidity of the cover according to the invention, it is possible to utilize for the cover in addition to steel rubberized on the interior, also other materials, as for example, synthetic material.

BRIEF DESCRIPTION OF THE DRAWING The figure is a perspective view partly in section of a horizontal electrolytic cell With mercury cathode and adjustable anodes and showing particularly the cell cover construction and a single rod or shaft connection for an anode, other connections being omitted.

BRIEF DESCRIPTION OF PREFERRED EMBODIMENT In this example, the cell cover 1 has downwardly extending groove-shaped projections 2 With trapezoidal cross section, in which are located the passage apertures 3 for the anode shafts 41. The plate-like anodes 6 are held through the shafts 4 by means of the plates 5 in the upper portion of the projections 2 of the cell cover, which is shown in lowered position at the right-hand part of the figure. With unworn anode plates, which here for simplification of the illustration are shown without shafts, the cover is in the position shown at the left band part of the figure. The anode shafts 4 as well as the under side of the cell cover are provided With a corrosion resistant protective layer 7 which may be rubber or a suitable synthetic material. The movability of the cell cover is insured by means of the flexible current supply strips 8 and a likewise flexible rim sealing strip 9. For stiffening of the cell cover in the direction not stiffened by means of the cover cross-section according to the invention, stiifening ribs 10 are provided. The adjusting mechanism for the cover is not shown on the drawing but it may take the form shown in U.S. Pat. 3,445,373, dated May 20, 1969.

What we claim is:

1. In an electrolytic cell provided With a bottom wall, side Walls, a mercury cathode and an anode carrying cover, the improvement which comprises a cover having a plurality of continuous, longitudinal, parallel channels having alternate upwardly and downwardly extending portions of trapezoidal form in cross section, anode shafts extending vertically through said downwardly extending channel portions of said cover, plate-like anodes to which said shafts are secured at their lower ends, and plates extending across the respective downwardly extending channel portions for holding said shafts in place.

2. In an electrolytic cell as claimed in claim 1, in which the cover is connected to the side walls by an elastic strip, stiifening ribs for said cover extending crosswise With respect to said channels.

References Cited UNITED STATES PATENTS 6/ 1952 Bennett et a1 204250 5/1967 Cotton et a1. 204219 U.S. C1. X.R. 204250 

